Yochi Dreazen at Vox says what we are all thinking:

In his seven chaotic months in office, President Trump has publicly insulted members of his own Cabinet, Senate Republicans, the hosts of Morning Joe, the Obama administration, and the nation’s intelligence services. He’s mused about firing special counsel Robert Mueller, publicly questioned America’s commitment to NATO, and threatened to punish Qatar, a vital Middle Eastern ally….

...Trump’s comments — many of which were improvised and came as a shock to his own advisers — threaten to take things in a very different, and very risky, direction. Each Trump threat ratchets up tensions with Pyongyang and makes it harder for North Korea’s status-conscious leaders to back down without seeming to lose face. Put even more starkly, Trump’s public comments and tweets are making war with North Korea more likely, not less so….

….As my colleague Zack Beauchamp has noted, North Korea “is deeply insecure [and] so worried about its own survival that it is willing to go to dangerously provocative lengths to scare the United States and South Korea out of any potential attack.”

That, in a nutshell, is what makes Trump’s comments so counterproductive, and so dangerous. Trump has chosen, apparently on his own, to explicitly talk about doing the things North Korea worries about most. President Theodore Roosevelt famously talked about speaking softly while carrying a big stick. When it comes to North Korea, Trump would do the entire world a favor if he went one step further and stopped speaking about North Korea at all.”

Besides, A-Hole, in a battle of face, what have you got to lose?